The present invention is directed to an apparatus for replacing pressing dies in an upsetting press used for width reduction of rolled material, such as the reduction of a slab width in a hot rolled wide strip shaping train in which die carries are arranged along opposite sides of the slab for supporting the pressing dies. A drive system moves the die carriers in the reducing direction in a horizontal stand between stand beams.
In German patent application P 39 17 398.4 an upsetting press is described with pressing dies supported in die carriers and located on the opposite slab edges for reduction of the slab width in a hot rolled wide strip shaping train. In the reduction drive, each pressing die along with its die carrier is moved in the direction of width reduction of the slab by a guide system actuated by a crank drive located within a crank housing. The crank drive is made up of two powered eccentric shafts with a connecting rod supported on each eccentric shaft and the head of each connecting rod is attached to the die carrier for transmitting the upsetting forces. A feed drive acting basically in the direction of the slab feed engages the die carrier. Such measures permit the control of the motion sequence of the pressing dies for the required reduction and for the feed of the pressing dies separately from one another. If the feed drive is an hydraulic drive, the displacement motion of the hydraulic cylinder can be controlled in a particularly effective manner in the form of a travel-time function whereby the synchronization of the motion of the pressing dies with the motion of the slab to be pressed from the sides is assured for every possible feed magnitude. This upsetting press enables a continuous reduction of the slab width to values preset by rolling technology. Such an arrangement of the upsetting press assures its high availability, so that a high productivity of the mill train, including the upsetting press, is assured.